This network of sensors monitors the natural carbon cycle and fossil fuel emissions, which help drive climate change.
In Boulder, NOAA's Earth System Research Lab, ESRL, is developing the tower network across the nation as part of its global observations of carbon cycle gases.
'Boulder and other cities are spending money to reduce their fossil fuel emissions. They need accurate data to know what is working and what is not,' says ESRL scientist Arlyn Andrews. 'With this new regional information, decisionmakers will be able to see if their emissions reductions have an impact on the atmosphere.'
Cities and states have relied on proxy data, such as point-source inventories and gasoline sales records to estimate fossil fuel emissions, but there has been no objective way to verify exactly what is released into the atmosphere.
Instruments on the towers are expected to give scientists detailed information on how the region's carbon dioxide is affected by forests, crops, or an upwind city.
Finding carbon monoxide in an air sample, for example, is a clue that the carbon dioxide source is a high-traffic urban area, since carbon monoxide is produced through combustion.
For the U.S. network, NOAA rents space on television broadcast towers up to 2,000 feet high - tall enough to capture air from several hundred miles upwind and give a regional view of atmospheric carbon levels.
The Erie tower is an exception. NOAA built it in the 1970s to gather wind, temperature, humidity and other weather data for research and forecasting, and it still collects those data. Known as the Boulder Atmospheric Observatory, the steel-scaffold structure supports two elevators that carry people and instruments to the top.
The carbon dioxide and carbon monoxide sensors sit in a six-foot metal frame at the base of the tower. They draw in air through tubes from three different levels along the tower.
Next year, ESRL scientists will begin gathering air in metal flasks, which will be sent to the Boulder lab for analysis. The flask samples will provide greater detail on sources of Front Range carbon emissions.
To date, the NOAA network includes active towers in Park Falls, Wisconsin; Moody, Texas; Argyle, Maine; and West Branch, Iowa.
Seven other sites are planned in Illinois, California, South Carolina, North Dakota, Nebraska, Alabama, and Ohio.
As other towers in the network collect regional details, the data will be fed into ESRL's online Carbon Tracker site in Boulder. Now geared to scientists, Carbon Tracker will ultimately provide local and regional information for policymakers, business leaders, teachers and the public.
'Eventually we'll be able to measure all of these effects — natural and human,' Andrews says. 'Nature has been giving us a break on carbon storage. If that starts to change, we need to be able to see it.'